1. Field of the Invention
The present application relates to laser emitting devices, method for making the same and use thereof.
2. Background of the Invention
Random laser devices have been known in the art For example, C. Zacharrakis, “Random lasing following two-photon excitation of highly scattering gain media Applied Physics Letters,” 81, 2511 (2002) discloses the use of a femtosecond pulse laser at the wavelength of 800 nm to two-photon excite Coumarin 307 colloid solution to obtain 480 blue emission. B. Raghavendra Prasad, et al, “Lasing in active, sub-mean-free path-sized systems with dense, random, weak scatterers,” Applied Optics, 36, 7718 (1997), discloses yellow emission by using a frequency-doubled Nd:YAG laser to pump colloid solution containing Rhodamine 590 perchlorate and polystyrene microspheres. S. John et al, “Theory of lasing in a multiple-scattering medium,” Phys. Rev. A, 54, 3642 (1996), H. Cao, “Lasing with resonant feedback in random media,” Physica B, 338, 215. (2003) and H. Cao, et al, “Transition from amplified spontaneous emission to laser action in strongly scattering media,” Physical Review E 61, 1985 (2000) have disclosed red emission in colloid solutions.
The above-mentioned-laser devices are in a generally liquid format. A skilled person in the art would appreciate that stimulated emission from polymeric solids is much more attractive in terms of applications, stability and cost However, up to now, very few workable polymeric systems have been reported. R. M. Balachandran, et al, “Laser action in polymeric gain media containing scattering particles,” Applied Optics 35, 640 (1996) and Y. Ling, et al. “Investigation of random lasers with resonant feedback,” Physics Review A 64, 063808-1 (2001) disclose red emission in PMMA at a threshold of 15 mJ/cm2.
However, the relatively high threshold of Balachandran and Ling's laser devices may restrict its applicability.
Furthermore, laser devices have been used in various applications such as for therapy purposes. For example, laser devices with wavelengths of 532 nm, 690 nm and 755 nm are known for their effect to eliminate or reduce black flecks, and a 585 nm laser can clean the red flecks, improve the skin properties and prevent aging. Exemplary applications of laser devices have been disclosed in various prior patents or patent publications, for example, in U.S. Pat. No. 5,625,456, entitled “Optical sources having a strongly scattering gain medium providing laser-like action” and issued to Nabil M. Lawandy on Apr. 29, 1997; PCT publication no. WO04026586A1, entitled “Random laser image projector system and method” filed by Timothy, J Miller on Sep. 16, 2003; U.S. Pat. No. 6,391,022, entitled “Ultra long pulsed dye laser device for treatment of ectatic vessels and method therefore” and issued to Furumoto et al on May 21, 2002; U.S. Pat. No. 6,551,308, entitled “Laser therapy assembly for muscular tissue revascularization” and issued to Muller et al on Apr. 22, 2003; U.S. Pat. No. 6,126,653, entitled “Laser therapy system and method of cutting and vaporizing a tissue body” and issued to John H. Hajjar on Oct. 3, 2000; U.S. Pat. No. 5,817,089, entitled “Skin treatment process using laser” and issued to Tankovich et at on Oct. 6, 1998; US patent publication on. 20020177844, entitled “Medical laser therapy device” and filed by Gerlach et al. on Jan. 10, 2002; U.S. Pat. No. 6,746,473, entitled “Therapeutic laser device” and issued to Shanks et al on Jun. 8, 2004; U.S. Pat. No. 6,312,451, entitled “Low level laser therapy apparatus” and issued to Jackson Streeter on Nov. 6, 2001; EP patent publication no. 1281378A entitled “Laser therapy Apparatus” and filed by Owa et al on Apr. 9, 2001.
However, the threshold restrictions on the laser devices using polymeric solids may inhibit the use of such lasers in these applications as well.